This invention relates to a trigger mechanism for a semi-automatic rifle, and more particularly to a positive latching-disconnecting mechanism for the transfer bar during he retraction of the bolt carrier.
In the trigger mechanism in a semi-automatic rifle, such as that disclosed in FIGS. 9 and 10 of my prior U.S. Pat. No. 4,677,897, and in my co-pending application Ser. No. 115,821, now U.S. Pat. No. 4,867,040 filed Nov. 2, 1987, for "SELF-UNLOCKING DEVICE FOR RECOILING BOLT CARRIER AND BARREL IN A SEMI-AUTOMATIC RIFLE", the trigger cooperates with a pivotal transfer bar and a vertically reciprocable sear for catching and holding (cocking) the firing pin in a retracted position when the trigger is relaxed and for releasing the firing pin to fire the cartridge, when the trigger is pulled.
After the cartridge is fired and while the bolt carrier is retracting, the cocking lever is pivoted to urge the rear hook on the firing pin beneath the sear hook. As the cocking lever moves rearwardly over the transfer bar, the transfer bar is normally depressed. The sear hook drops and engages the rear hook of the firing pin, in order to cock the firing pin. However, on occasions, and particularly as the cooperating parts of the trigger mechanism become worn, the transfer bar may slip and remain in or return to an upper position. When the bolt carrier returns to its battery position, the sear will be forced upward by the elevated transfer bar to release the firing pin. Since the firing pin is not held in its retracted position, it will continue to repetitively move forward and fire, retract, move forward and fire, as long as the trigger is held in its rearward position. Thus, the semi-automatic rifle becomes a fully automatic rifle when such action is not desired.